Wing structure for flying machines



July 18, 1933.

' L. BREGUET WING STRUCTURE FOR FLYING MACHINES Filed Jan. 28, 1932 2 Sheets-Sheet l Juu 18, 1933. L BREGUET 11,919,88

WING STRUCTURE FOR FLYING MACHINES Filed Jan. 28, 1932 2 Sheets-Sheet 2 fm /eiyior WQM YXA Calm/M airplane,

an orthogona increase the rigidity of the tr ss "in Application The most preval nt form of airplane w' structure, since av; ti-on comprises essentially two spars, disposed at right angles to the fore and aft direction of the and ci'innectcd to each other through struts which form with said spars l system which is braced by means of rigid or flexible diagonal members, such as tubes, wires or tie rods. That system is further provided with ribs which have a shape correspondi to the desired profile ot' the wing, and which are secured to said spars regular intervals and right angles thereto. The covering, of lab ric, veneer, or sheet metal, surrounds the ribs to which it is secured. Lastly, the ing edge and the trailing edge consi t ot a special member of appropriate shape, such as a false spar, a sectional iron, or a cable.

That usual mode of construction has several dJaWba-cks. Tie tollo "ing drawbacks may be cited, among others:

(a) in wings the structure of which, consisting of spars and c members, is brac d by means of wires, cables or ti rods, the adjustment or the tension of these flexible organs is a rather delicate op eration, which must be checked or made over again at periodical intervals;

(b) the two spars, which must be disposed far apart as possible, in order to l t they form in the plane of the wing, are located at points of the profile of the wing where the thickness of said wing small, due to the proximity of the leading dge or of the trailing edge, which correpondinglyreduces the height of said spars and their capacity of withstanding bending moments j p (c) the resultant of the aerodynamic actions to which the wing is subjected is materially displaced when of incidence varies, so that the loadscn the two spars of the wing areuneqnal and vary su stantially with the cond ions of flight;

(d) a above stated, the utilisation et two spars does not avoid the necessity of employing accessory pieces in the tornrot spars or false spars for constituting the orrcspoiiding diagonal relates 3230. 589,439, and in France March 25, 1931.

ture which avoids or lessens the above mentioned drawbacks and further provides some new advantages.

Preferred embodimentsof my invention will be hereinafter described with reference to the accompanying drawings, given merely by way of example, and in which:

in: 1 is an elevational view diagrammatically showing the structure according to my invention, 7

Fig. 2 .is a plan view corresponding to Fig. 1; i

3 is a sectional view of a practical embodiment, on a line parallel to the direction of a diagonal member 4i of Fig. 1;

Fig.4 is a corresponding detail view an enlarged scale; I

I, Fig. 5 is a sectional view on the line mw of Fig. 3. 7

in the diagrammatical showing of Figs. 1 and-2, thewi'ng structure according to my invention essentially comprises:

(a) main spar 1, located at the point where the protile ot the wlng has a mainpart Oi the wing are pivoted the ailerons or auxliary snri aces 3, such as ailerons for the lateral control and surfaces for varying the curvature oi: the wing;

(c) obliqne or diagonal and consecutive braces l, win'ca connect the main spar 1 to tliefsecond ry spars 2 and? each of said ussthe constituents of which are isd I '1.

hand, and secondary spars '2 and 3 on "the ngot rigid pieces, so as to i close to the contour-ofthe wing outer part of which they bear.

other hand. Said pieces 5 are disposed at right angles to the direction of the spars, that is to say in a parallel direction to the fore and aft direction of the airplane. When the covering of the wing is supple, said laths 5 extend over oblique braces 4 on the Said laths serve to ensure the regular shape of the profile of the wing in a plane parallel to the fore and aft direction of the airplane and to secure the supple covering. When the covering is rigid, and, in particular, when it is metallic, the oblique braces 4 above described may conform exactly with the shape of the surface of the covering. In the latter case, lath; 5, instead of being disposed upon said, braces l are ecured to the latter, while also conforming in shape to the surface of tie covering, which is then secured both to obl que braces at and to laths 5.

Furthermore, I may dispose, between laths 5, and at the points Ga at which oblique braces 4 are secured to spars 2 and 3, intermediate laths 6, lighter than laths 5 and which only serve to maintain the regular shape of thewing profile forthe covering which is secured to them. In the case, for instance of a covering of thin metallic plates, said intermediate laths play the part of an inner corrugation of the metal and serve to stiffen the latter for increasing the resistance of the covering to torsional stresses. Said intermediate laths are optional.

The wing thus formed constitutes a fiat trussed box, braced in all directions by means of rigid pieces only, such a box being consequently not liable to get deformed.

Owing to the maximum height of the main spar, said structure utilizes remarkably well the matter of said spar for absorbing bending stresses and compressive stresses.

Owing to the fact that the leading edge and the rear edge of the fixed part of the wing profile consist of secondary spars, said parts are given a great rigidity and are efiiciently utilized for absorbing compressive and bending stresses.

Owing to the maximum space existing between these two secondary spars, the structure accordin to my invention is better adapted to withstand the stresses resulting from head resistance which tend to bend the ing in lts own plane.

Finally, owing to the bracing and trussing in all directions of the wing structure, by means of the oblique braces t, and owing to the arrangement of the elements of the wing structure in such a manner that they are as close as possibly to the periphery of the wing, said structure is remarkably resistant to stresses tending to twist'the wing-about itself.

Furthermore,in the case of wings of socalled rectangular shape, or of wings of sub stantially equivalent shape, my invention makes it possible to utilize simple wing elements, identical from one portion of the wing to another one, and obtained by means of a simple equipment.

In the case of a wing made as above explained and braced by means of uprights and tie rods, the fixation of said uprights or tie rods to the structure of the wing may be made either on the main spar 1 according to the known means, or, also according to the known means, on the secondary spars 2 and 3, or on one of the last mentioned spars and on the main spar. In the two last cases, the secondary spar to which said bracing members are secured is connected to the main spar through a reinforced connection. Such a connection may consist, in particular, either of a box-shaped rib forming a direct bracing according to the known arrangements, or of the Very oblique braces 4 above referred to, which are then suitably reinforced.

In order to better explain certain details of the wing construction according to my invention, I have shown in Figs. 3 to 5, by way of example, an embodiment of a wing structure of the type according to my invention.

Said example relates to the case of a wing having a supple covering and therefore to the case in which, as above stated, the covering is fixed only to laths 5 and 6 which are at right angles to the spars and serve to fix the profile of the wing, said laths bearing upon oblique braces 4 over which they are disposed. I

The front spar consists of the web 20*. provided with longitudinal corrugations so as to increase its resistance to compression and to buckling, and of a sheet forming the leading edge proper, web 2a and sheet 26 being maintained by means of transverse pieces 20 made of sheet iron, suitably stamped and hollowed out, which are regularly spaced along the leading edge of the wing and the rectilinear vertical edge of which serves tofix, at 19, 20, and 21, web 2a and to einrure its resistance to transverse shearing.

The main spar 1 consists of two webs such as 1a, corrugated in the transverse directiim, and assembed to two treads 1b which may be longitudinally corrugated, webs 1c being then braced from place to'place by means of gussets such as 22 or of spaced frames.

Besides, in a general manner, the main spar may be constructed in any way whatever, the only necessarycharacteristic of my invention concerning said construction being that the treads of said spar are part of the profile of the wing, and that braces i and laths 5 and (Bare secured to said spar on the upper and lower, outer portions thereof.

The oblique braces 4 (Figs. 1 and 3) form, together with uprights or rods 7, a vertical truss. Said braces consist of sectional irons, such as L -shaped irons with flanged edges (Fig. el) closed at certain places by means of small pl -'s 9 secured to the flanges of said O irons. 1 racing rods '4' may, for example, consist of ei-shaped sectional i as inserted inside races l, as shown in Fig. and which are s cured thro 1 known means, and in particular t l nrougli riveting, with the ac.- unetion of an assembling gusset, it need be. liarns arv secured to the whole of beam l and bracing rod 7 in the same vertical lines as the points at which said elements are secured iner, a piece being interposed, need be, between said laths 5 and elements shown in Figs-3 and 5. Fig. i is a perspective view of a detail of the assemblingot two contiguous oblique braces -l with the web 2c of the front spar. It wil be seen that each brace at is secured, on the one hand, to the flanges er ge 2d, and on the other hand to the upper plane portion no of the web proper 2a or the span.

The fixation is obtained by means of two gusset-s made of sheet iron. The upper gusset 12, to which brace 4 is secured by means of rivets is fixed to the fianged edge 21 l y means of rivets l6 and 17 located in parts of gusset 12 which are suitably slanted by stamping so as to provide for the eventual dili'erence of inclination between flanged edge 24 and 1e upper plane face of br ce at. The lower a 13, which is also suitably shaped by s'' ing, is fixed to the flange d wings of brace l by means of rivets l-l and to part in of the web 2c of the spar by means of rivets 18. a

l hile I have disclosed what I deem to be preferred embodiments of my invention. it should be well understood that I do not wish to be limited thereto as there might be cha iges made in the arrangement, disposition -=l tr m of the parts without depart- .i rom the principle of my invention as comprehended within the scope or the appended claims.

l w hat I claim is: 1. An airplane wing structure of the type e comprising in combination, a main 7 to the fore and aft dior the 21111313116 located in the part the profile of the wing f'TirGlG the thickthereof is maximum, two secondary parallel to the first mentioned one, one 1 secondary spars forming the leading edge 0 he wing and the other one forming the rear edge of the fixed part of said wing, of bracin members forming a icing between the main spar and mentioned secondary spar, a pluit? of bracing members forming a ziging between the main spar and the second menti red secondary spar, and a plu- L of light members extending between said main spar and said secondary spars at right angles thereto, adapted tosupport the wing covering.

2. An airplane wingstructure of the type described comprising in combination, a main spar located at a distance from the leading edge or the wing substantially equal to one third of the chord of said wing, and the vertical dimension of which is equal to the thickness 01" the wing at that point, two secondary spars parallel to the first mentioned one and at right angles to the fore and aft direction of the alrplane, one of said secondary spars forming the leading edge of the wing and the other one torming the rear edge of the fixed part of said wing, a plurality oi bracing members tormmg a Z1g-Zag latticing between said main spar and the ness thereof is maximum, said main sparhaving a vertical dimension which is equal to the thickness .01 the wing at that point, two secondary spars parallel to the first mentioned one, 0ne of said secondary spars forming the leading edge of thewing and the other one forming tae rear edge of the fixed part of said wing, a plurality of bracing members forming a zig-zag latticing between said main spar and the first mentioned secondary spar, a plurality of bracing members forming a Zigzag lattieing between the main spar and the second mentioned secondary spar, each of said bracing members consisting of a plurality of rigid elements assembled in such manner as to form a trussed structure located in a vertical plane obliquely disposed with respect to-.said s1: ars, said elements being disposed as close to the con tour of the wing profile asit is possible, and a plurality of light membersextending between said main spar and said secondary spars at right angles thereof, adapted to support the wing covering.

at. An airplane wing structure according to claim 3 in which the light members at right angles to said spars extend over and across said bracing members, such an ar- 7 rangement being especially intended for the case of a flexible wing covering.

5. An airplane wing structure of the type described comprising 1n combination, a main spar at r1ght angles to the fore and aft direction of the airplane located 111 the part J1 J. or the profile or the wing where the thickness is maximum, said main spar havinga vertical dimension which is equal to the thickness of the Wing profile at that point, two secondary spars parallel to the first mentioned one, one of said secondary spars forming the leading edge of the Wing and the other one forming the rear edge of the fixed part of said Wing, a plurality of bracing members forming a zig-zag latticing between said main spar and the first mentioned secondary spar, a plurality of bracing members forming a zig-zag latticing between said main spar and the-second mentioned secondary spar, each of said bracing members consisting of a plurality of ri 'id elements assembled in such a manner as to form a trussed structure located in a vertical plane, the outer elements of said structure conforming in shape with the external surface of the wing, and a plurality of light members at right angles to said spars secured to said outer elements of the trussed structure of the bracing members, whereby a covering of thin metal plates can be secured directly to said bracing members and to said light members.

6. An airplane Wing structure according to claim 3 in which some of the bracing elements are reinforced so that external bracingmembers can be secured to at least one i the spars at points corresponding to said reinforced bracing members.

LOUIS BREGUET. 

